Association of Admission Blood Glucose Level with All-Cause Mortality According to Age in Patients with Community Acquired Pneumonia

Figures & data

Table 1 Inclusion and Exclusion Criteria

Inclusion criteria

(1) Community onset; (2) Presence of new infiltrate on chest X-ray or computed tomography scan together with at least one of the following: (i) New or increased cough (productive, nonproductive or with a change in sputum characteristics) with or without dyspnea, chest pain or hemoptysis; (ii) fever; (iii) Rales and/or signs of consolidation; (iv) Peripheral WBC counts >10,000 cells/mm^3 or <4000 cells/mm^3, with or without a left shift toward immature forms.

Exclusion criteria

(1) Acquisition of pneumonia after hospital admission or patients re-admitted after hospital discharge of <28 days; (2) Presence of severe immunosuppression associated with a relevant risk of opportunistic infection, ie chemotherapy and/or neutropenia of <1000 neutrophils/mL during the last 28 days, therapy with >20 mg/day corticosteroids for >14 days, known HIV infection and/or immunosuppressive therapy after organ or bone marrow transplant; (3) Pneumonia as an expected terminal event of a severe chronic disabling comorbid condition; (4) An alternative diagnosis evolving during follow-up.

Table 2 Demographic and Clinical Characteristics at Admission

	Total	Middle-Age (45–59 Yrs)	Elderly (≥60 Yrs)	P value
N	1656	592	1064
Demography
Age, yrs	67.8±9.8	54.5±9.2	75.2±10.3	<0.01
Male, n (%)	927 (56.0%)	361 (61.0%)	566 (53.2%)	<0.01
Current smoker, n (%)	412 (24.9%)	255 (43.1%)	157 (14.8%)	<0.01
Comorbidities, n (%)
Ischemic heart disease	374 (22.6%)	69 (11.7%)	305 (28.7%)	<0.01
Malignancy	278 (16.8%)	89 (15.0%)	189 (17.8%)	0.17
Kidney disease	245 (14.8%)	61 (10.3%)	184 (17.3%)	<0.01
Diabetes mellitus	215 (13.0%)	56 (9.5%)	159 (14.9%)	<0.01
Cerebrovascular disease	189 (11.4%)	31 (5.2%)	158 (14.8%)	<0.01
Congestive heart failure	119 (7.2%)	25 (4.2%)	94 (8.8%)	<0.01
Asthma	119 (7.2%)	38 (6.4%)	81 (7.6%)	0.43
Chronic obstructive pulmonary disease	91 (5.5%)	8 (1.4%)	83 (7.8%)	<0.01
Bronchiectasis	53 (3.2%)	18 (3.0%)	35 (3.3%)	0.88
Chronic liver diseases	17 (1.0%)	5 (0.8%)	12 (1.1%)	0.80
Physical examination, n (%)
Altered mental status	55 (3.3%)	6 (1.0%)	49 (4.6%)	<0.01
Tachycardia (pulse rate≥125/min)	188 (11.4%)	75 (12.7%)	113 (10.6%)	0.23
Respiratory rate≥30/min	45 (2.7%)	10 (1.7%)	35 (3.3%)	0.06
Systolic blood pressure<90 mmHg	78 (4.7%)	24 (4.1%)	54 (5.1%)	0.40
Temperature<35°C or ≥40 °C	81 (4.9%)	28 (4.7%)	53 (5.0%)	0.91
Laboratory and radiologic measures, n (%)
Blood glucose≥11.1 mmol/L	172 (10.4%)	58 (9.8%)	114 (10.7%)	0.61
Blood urea nitrogen ≥7 mmol/L	340 (20.5%)	77 (13.0%)	263 (24.7%)	<0.01
Hematocrit<30%	294 (17.8%)	79 (13.3%)	215 (20.2%)	<0.01
Hypoxemia (PaO2<60 mmHg or SaO2 <90%)	180 (10.9%)	61 (10.3%)	119 (11.2%)	0.62
Arterial pH<7.35	102 (6.2%)	35 (5.9%)	67 (6.3%)	0.26
Pleural effusion	563 (34.0%)	209 (35.3%)	354 (33.3%)	0.65
Etiology
Mycoplasma pneumonia	127 (7.7%)	68 (11.5%)	59 (5.5%)	<0.01
Streptococcus pneumonia	105 (6.3%)	38 (6.4%)	67 (6.3%)	0.92
Haemophilus influenzae	87 (5.3%)	30 (5.1%)	57 (5.4%)	0.91
Chlamydia pneumoniae	72 (4.3%)	25 (4.2%)	47 (4.4%)	0.90
Klebsiella pneumoniae	27 (1.6%)	8 (1.7%)	17 (1.6%)	0.83
Staphylococcus aureus	20 (1.2%)	6 (1.0%)	14 (1.3%)	0.65
Legionella pneumophila	14 (0.8%)	6 (1.0%)	8 (0.8%)	0.58
Escherichia coli	15 (0.9%)	6 (1.0%)	9 (0.9%)	0.79
CURB-65
0–1	500 (30.2%)	415 (70.1%)	85 (8.0%)	<0.01
2	683 (41.2%)	139 (23.5%)	544 (51.1%)
3–5	473 (28.6%)	38 (6.4%)	435 (40.9%)
ICU admission	120 (7.2%)	35 (5.9%)	85 (8.0%)	0.14
Length of stay (days)	13.09 ± 9.9	12.7 ± 9.6	13.3 ± 10.3	0.71

Figure 1 Kaplan–Meier survival curves for inpatients with community acquired pneumonia (CAP) according to blood glucose level (A), age (B), blood glucose level in middle-age subjects 45–64 years (C), and blood glucose level in elderly ≥65 years (D).

Table 3 Univariate Analysis of Risk Factors for 28-Day Mortality in Patients with Community-Acquired Pneumonia (CAP)

	OR	95% CI	P value
Demography
≥60 yrs vs 45–59 yrs	2.41	1.82–3.20	<0.01
Male vs Female	1.68	1.09–2.27	0.02
Current smoker vs Non-smoker	1.45	0.87–1.95	0.18
Comorbidities
Ischemic heart disease	1.42	0.75–1.98	0.13
Malignancy	2.13	1.37–3.10	<0.01
Kidney disease	1.65	1.17–2.37	0.01
Diabetes mellitus	2.09	1.43–2.88	<0.01
Cerebrovascular disease	1.66	0.92–2.51	0.19
Congestive heart failure	2.25	1.67–3.29	<0.01
Asthma	1.47	0.97–1.89	0.09
Chronic obstructive pulmonary disease	1.31	0.77–2.01	0.45
Bronchiectasis	1.25	0.65–1.87	0.53
Chronic liver diseases	1.64	0.89–2.33	0.18
Physical examination
Altered mental status	1.72	1.32–2.43	<0.01
Tachycardia (pulse rate≥125/min)	1.88	1.41–2.75	<0.01
Respiratory rate≥30/min	1.59	1.10–2.03	0.01
Systolic blood pressure<90 mmHg	1.82	1.35–2.43	<0.01
Temperature<35°C or ≥40 °C	1.16	0.57–1.64	0.82
Laboratory and radiologic measures
Blood glucose≥11.1 mmol/L	2.36	1.46–3.82	<0.01
Blood urea nitrogen ≥7 mmol/L	2.03	1.28–3.26	<0.01
Hematocrit<30%	1.65	0.76–2.32	0.43
Hypoxemia (PaO2<60 mmHg or SaO2 <90%)	1.56	1.17–2.19	0.02
Arterial pH<7.35	1.89	1.34–2.77	<0.01
Pleural effusion	2.15	1.76–3.17	<0.01
Etiology
Mycoplasma pneumonia	1.06	0.53–1.85	0.65
Streptococcus pneumonia	0.86	0.48–1.76	0.73
Haemophilus influenzae	1.35	0.65–1.98	0.87
Chlamydia pneumoniae	0.91	0.76–1.18	0.49
Klebsiella pneumoniae	1.19	0.31–2.05	0.82
Staphylococcus aureus	0.65	0.39–1.18	0.32
Legionella pneumophila	0.88	0.65–1.08	0.20
Escherichia coli	0.92	0.71–1.32	0.90
CURB-65
0–1	Ref.
2	1.86	1.32–2.75	<0.01
3–5	2.36	1.80–3.13	<0.01
ICU admission	2.71	1.99–3.86	<0.01
Length of stay	1.32	0.81–1.76	0.25

Table 4 Multivariate Analysis for Evaluating the Association of Blood Glucose Level and Age with 28-Day Mortality in Patients with Community Acquired Pneumonia (CAP)

	Multivariate Analysis*
	Hazard Ratio	95% CI	P value
All population
Blood glucose level ≥ vs < 11.1 mmol/l	2.08	1.38–3.49	<0.01
Age ≥ vs < 60 yrs	2.76	1.65–3.77	<0.01
Middle-age (45–59 yrs)
Blood glucose level ≥ vs < 11.1 mmol/l	4.48	1.40–13.65	<0.01
Elderly (≥60 yrs)
Blood glucose level ≥ vs < 11.1 mmol/l	1.52	1.09–2.17	0.05

Notes: *Hazard ratios with 95% CIs were calculated using the multivariate Cox proportional-hazards regression, after adjustment for gender, malignancy, kidney disease, diabetes mellitus, congestive heart failure, asthma, altered mental status, tachycardia, respiratory rate, systolic blood pressure, blood urea nitrogen, hypoxemia, arterial pH, pleural effusion, CURB-65, and ICU admission.